From b81a57e8eba9b74dbe4961ff0a910303fdaf0632 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Wed, 23 Nov 2016 21:22:08 +0200 Subject: [PATCH] config, dht: reduce default msb ignore bits to 4 With the default value of 12, a node's range is partitioned into 4096 * smp::count sub-ranges which are queried sequentually for a range scan. If the number of rows in the table is smaller than the required result size, we will query all of them. This can take so long that we time out. A better fix is to query multiple sub-ranges in parallel and merge them, but for that we need to resurrect the non-sequential merger. --- db/config.hh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/db/config.hh b/db/config.hh index 781498dd3f..bb79d00a65 100644 --- a/db/config.hh +++ b/db/config.hh @@ -737,7 +737,7 @@ public: val(prometheus_port, uint16_t, 9180, Used, "Prometheus port, set to zero to disable") \ val(prometheus_address, sstring, "0.0.0.0", Used, "Prometheus listening address") \ val(abort_on_lsa_bad_alloc, bool, false, Used, "Abort when allocation in LSA region fails") \ - val(murmur3_partitioner_ignore_msb_bits, unsigned, 12, Used, "Number of most siginificant token bits to ignore in murmur3 partitioner; increase for very large clusters") \ + val(murmur3_partitioner_ignore_msb_bits, unsigned, 4, Used, "Number of most siginificant token bits to ignore in murmur3 partitioner; increase for very large clusters") \ /* done! */ #define _make_value_member(name, type, deflt, status, desc, ...) \